New species of marine worm discovered on the Antarctic Deception Island

The new species is part of a group of marine worms (polychaetous annelids) which commonly occur in marine seabed rich in organic matter -- from both natural and anthropogenic origin -- at different latitudes. To be exact, P. diapason is the second species of the genus Parougia discovered in the Southern Ocean (P. furcata was described in 1953 by O. Hartman).

A new species on the seabed of Deception Island

Experts identified this small marine worm in bones of a common minke whale (Balaenoptera acutorostrata) in Port Foster shallow waters, on Deception Island, close to the Gabriel de Castilla Spanish Antarctic base, but also in association with organically enriched sediments nearby. "The Antarctic Peninsula and South Shetland Islands are a widely studied area. However, few species have been described so far on Deception Island," affirms Professor Conxita Àvila, head of the multidisciplinary project DISTANTCOM, which studies chemical ecology, phylogenetics, phylogeography and trophic ecology in the Antarctic continent.

Marine worms that feed on whale bones: live after death

According to researcher Sergi Taboada, first author of the article, "there are few scientific studies centred on marine invertebrate communities associated with whale bones in the Antarctica. Our group is pioneer in this type of studies which are also being developed in other Earth's regions."

Experts have carried out morphological and phylogenetic analyses (with nuclear and mitochondrial genetic markers) to determine the new species. Evidence suggests that it is the most ancient species of the genus Parougia. The species present some morphological traits -- it lacks the dorsal cirrus and has some particular morphological characters related to the jaw apparatus -- that distinguishes it from the rest of congeneric species described so far.

"The study ―highlights Taboada― provides comprehensive information about the new species, not only from a morphological and ecological point of view, but also places the species in its phylogenetic context." "In the past, this type of information was not available but, lately, it is more and more common to find species descriptions that include a phylogenetic tree. Moreover, this kind of information is collected on public databases that every interested researcher can consult."

Parougia diapason, an opportunistic species

One of the most interesting scientific aspects is the ecology of the species discovered in the Antarctica. These organisms, which quickly colonised a territory presenting some altered characteristics, signal areas rich in organic matter, both from natural and anthropogenic origin.

"It seems that P. diapason ―points out Taboada― is an organism that signals any kind of environment alteration like a significant increase of organic matter." "The species -- he adds -- is a clear example of an opportunistic species, in other words, an organism that takes profit of particular conditions (an excess of organic matter) that favour its proliferation and population density." Knowledge of these ecological characteristics is crucial as it allows detecting environmental changes in an indirect way.

There is not much scientific literature about Antarctic marine benthic organisms that proliferate in eutrophic habitats (rich in organic matter). There are some studies centred on anthropogenic activity impact in the McMurdo base ―the largest American scientific base in the Antarctica― to monitor marine invertebrate communities in the area where waste water was dumped.

Antarctic new species discovery and protection

The UB-IRBio research team has made other significant discoveries of Antarctic marine invertebrates, for example the two first bone-eating worms of the genus Osedax, or the nemertean Antarctonemertes riesgoae that has a unique reproductive strategy. However, scientists ensure that there is still so much work to do in order to explore, discover and, the most important, to protect the Antarctica.

"It is necessary to continue studying new species and to do our best to protect them," emphasizes Conxita Àvila. "The Antarctica has very special habitats which are difficult to study; measures must be maximized in order to avoid, for instance anthropogenic pollution and tourism impact."

"Any change can affect Antarctic regions but we do not have enough data yet. However, it is sure that these changes can cause the extinction of species which remain unknown and unstudied. Besides biodiversity loss, species extinction means missing the opportunity to study the chemical products they elaborate which may be molecules with potential biological interest," alerts Conxita Àvila.